Short Answer:
Functional Medicine is an approach of looking at your symptoms and asking why do you have them? Where are they coming from? Specifically, what is the root cause, since any symptom can come from many causes? Functional medicine approaches the body as a system of interconnected processes, so we ask, what process is not working optimally and why? Then we direct our healing to those systems that are out of balance.
Deeper Answer:
Functional Medicine, I believe will soon be the way care is delivered because it effectively addresses the health and wellness needs of our times.
Conventional medicine operates at its best in acute care: accidents, heart attacks, strokes, infections. And does it very effectively. However, most people have chronic issues such as heartburn, constipation, thyroid issues, arthritis, hypertension, diabetes, to name a few common conditions.
What is more typical is they just are not feeling their best and don’t know why. They don't have a "diagnosis" of a condition but feel off: tired, not sleeping well, more irritable than normal, crave certain foods, or eat mostly processed foods, or they just have much energy to do the things they want to.
Conventional medicine approaches sickness as a set of symptoms that get put in buckets, each bucket gets labeled a disease or condition which are typically addressed by finding a drug that minimizes the symptoms or their impact, so overall you feel better.
But the condition is never fully resolved and so no plan is made to “end” the use of medications, and more often than not, the side effects can be just as bad as the condition it is supposed to improve.